- Feng Qi, Cristinel Mortici, “Some best approximation formulas and inequalities for the Wallis ratio”, Applied Mathematics and Computation, 253, 2015, 363
- Feng Qi, Mansour Mahmoud, “Bounding the gamma function in terms of the trigonometric and exponential functions”, Acta Sci. Math., 83, № 1-2, 2017, 125
- Feng Qi, Wen-Hui Li, “A LOGARITHMICALLY COMPLETELY MONOTONIC FUNCTION INVOLVING THE RATIO OF GAMMA FUNCTIONS”, jaac, 5, № 4, 2015, 626
- Cristinel Mortici, Feng Qi, “Asymptotic Formulas and Inequalities for the Gamma Function in Terms of the Tri-Gamma Function”, Results. Math., 67, № 3-4, 2015, 395
- Xiaodong Cao, Ruopeng Wang, “Some inequalities for the ratio of gamma functions”, J Inequal Appl, 2015, № 1, 2015, 178
- Feng Qi, Cristinel Mortici, “Some inequalities for the trigamma function in terms of the digamma function”, Applied Mathematics and Computation, 271, 2015, 502